Folding formers are frequently used in paper handling apparatus associated with printing machines to generate a longitudinal fold in a substrate web, typically a paper web. Some special type of printed copy products which are to be made from the web received, by subsequent paper handling, require the formation of subsequent transverse folds, longitudinal folds and the like. Association of a folding former, as well known, with subsequent paper handling apparatus, frequently requires a shift of the folding former triangle of one or more paper webs being applied to the longitudinal apparatus which includes the folding former.
The shift of the folding former is desired to offset the tip of the folding triangle or folding funnel or former apparatus in a horizontal direction, transverse to the axis of an inlet roller; in other words, the crease line generated by the folding former is to be lifted, or depressed, that is, is to be adjustably arranged with respect to the former run-on or web supply roller. In accordance with a prior construction, for example as used in printing machines of the type "ROTOMAN" (trademark), manufactured by the Assignee of the present application, the tip of the folding former can be horizontally shifted. This requires repositioning of the run-on or supply roller as well, since the entire folder is shifted; this shift of the supply roller changes the angle about which the paper web is looped, thus changing the tensioning relationships of the paper web. The former run-on or supply roller is a driven roller, coupled to the drive system of the printing machine from which the web is derived. Thus, shifting the supply roller is comparatively complex and requires subsantial structural modifications. In some constructions, it has been found suitable to provide a separate supply or run-on roller if only one of several folding formers are to be shifted.
Shift of only one of a plurality of, for example parallel folding formers, is sometimes desirable, or required, so that the supplied webs will have different ridge positions, thus permitting grippers to more readily engage the respective folded webs which, as part of the folding operation, may also be slit or separated into parallel strips. Slitting and cutting apparatus, combined with folding formers, are well known.